What does sslReadClient: FD 14: read failure: (104) Connection reset by peer mean?
“Connection reset by peer” is an error code that Unix operating systems sometimes return for read, write, connect, and other system calls. Connection reset means that the other host, the peer, sent us a RESET packet on a TCP connection. A host sends a RESET when it receives an unexpected packet for a nonexistent connection. For example, if one side sends data at the same time that the other side closes a connection, when the other side receives the data it may send a reset back. The fact that these messages appear in Squid’s log might indicate a problem, such as a broken origin server or parent cache. On the other hand, they might be “normal,” especially since some applications are known to force connection resets rather than a proper close. You probably don’t need to worry about them, unless you receive a lot of user complaints relating to SSL sites. Rick Jones notes that if the server is running a Microsoft TCP stack, clients receive RST segments whenever the listen queue overflo